darexaban and apixaban

Approximately 900,000 people are affected by some sort of venous thromboembolic (VTE) event every year in the United States. VTE diagnosis used to mean treatment with medications that required routine lab monitoring for safety and efficacy. Activated factor X (FXa) inhibition has emerged as a convenient pathway for management of VTE and currently three FXa inhibitors are available for anticoagulation management - rivaroxaban, apixaban, and edoxaban. Continued development of medications utilizing this pathway may offer advantages via novel pharmacokinetic or pharmacodynamic properties that may minimize the adverse effects associated with traditional anticoagulant therapy. This review summarizes the available information regarding pharmacokinetic, pharmacodynamic, and early safety and efficacy data for three factor Xa inhibitors being developed - darexaban, betrixaban and nokxaban. The studies reviewed in this article suggests that three newer agents possess the potential for promise based on early phase I and II trials.

Topics: Administration, Oral; Animals; Azepines; Benzamides; Blood Coagulation; Drug Discovery; Factor Xa Inhibitors; Humans; Pyrazoles; Pyridines; Pyridones; Rivaroxaban; Thiazoles; Venous Thromboembolism

A meta-analysis was performed to evaluate the risk of major bleeding with the use of New Oral Anticoagulants (NOACs).. Randomized controlled trials (RCTs) comparing NOACs (rivaroxaban, dabigatran, apixaban, edoxaban and darexaban) with comparators were selected.. Fifty trials included 155,537 patients. Pooled analysis of all NOACs for all indications together demonstrated no significant difference between NOACs and comparators for risk of major bleeding (odds ratio [OR] 0.93, 95% CI 0.79-1.09). Pooled analysis also showed that NOACs caused significantly less major bleeding compared to vitamin K antagonists (VKA) (0.77, 0.64-0.91). The analysis for individual NOACs showed risk of major bleeding were not different with rivaroxaban, apixaban or dabigatran compared to pharmacologically active comparators or VKA. Indication specific analysis showed that NOACs were associated with significantly higher major bleeding after hip surgery (1.43, 1.02-1.99), in patients with acute coronary syndrome (ACS), (compared against placebo) (2.89, 2.01-4.14), and for medically ill patients (2.79, 1.69-4.60). For the treatment of acute venous thromboembolism (VTE) or pulmonary embolism (PE), NOACs were associated with significantly less bleeding (0.63, 0.44-0.90). No significant difference was found between NOACs and comparators in treatment of atrial fibrillation and for extended treatment of VTE.. Risk of major bleeding with new oral anticoagulants varies with their indication for use. New agents may be associated with comparatively less major bleeding compared to VKA. NOAC may increase the risk of major bleeding after hip surgery, ACS and acute medically ill patients; but may be associated with less bleeding in treatment of acute VTE/PE.

Topics: Administration, Oral; Antithrombins; Azepines; Benzamides; Benzimidazoles; beta-Alanine; Dabigatran; Factor Xa Inhibitors; Hemorrhage; Humans; Morpholines; Pyrazoles; Pyridines; Pyridones; Randomized Controlled Trials as Topic; Risk; Rivaroxaban; Thiazoles; Thiophenes

Despite widespread adoption of acetylsalicylic acid and P2Y12 receptor inhibitor therapy as the standard of care for secondary event prevention in patients with acute coronary syndrome (ACS), the rate of cardiovascular death or myocardial infarction following discharge is approximately 24-31% over five years, indicating an important unmet need to reduce further the risk of recurrent ACS events. Because thrombin has a role in arterial thrombus generation, a mechanistic rationale exists for adding an anticoagulant to dual antiplatelet therapy to reduce cardiovascular event rates and mortality. The direct thrombin inhibitor dabigatran and the direct Factor Xa inhibitors rivaroxaban and apixaban have been investigated for this application, with only rivaroxaban successfully completing a phase III trial. These results suggest that dose selection is of paramount importance in this indication, with lower anticoagulant doses (relative to those used in other indications, such as stroke prevention in atrial fibrillation) plus low-dose acetylsalicylic acid potentially improving cardiovascular outcomes. This article reviews clinical trial data of anticoagulants for secondary event prevention in patients with ACS; it also discusses the mechanistic reasons that may underlie these observations and looks towards the potential impact of findings from the ATLAS ACS 2 TIMI 51 trial on clinical practice.

Topics: Acute Coronary Syndrome; Administration, Oral; Anticoagulants; Azepines; Azetidines; Benzamides; Benzimidazoles; Benzylamines; beta-Alanine; Dabigatran; Humans; Morpholines; Pyrazoles; Pyridones; Rivaroxaban; Thiophenes; Thrombin; Vitamin K

Despite an early invasive strategy and the use of dual antiplatelet therapy, patients with acute coronary syndrome (ACS) continue to be at substantial risk for recurrent ischemic events. It is believed that this risk is, at least in part, due to an intrinsic coagulation pathway that remains activated for a prolonged period after ACS. Earlier studies using warfarin showed a reduction in ischemic events, but the overall benefits were offset by increased bleeding complications. Recently, there has been increased interest in the potential role of new oral anticoagulants, some of which target factor Xa, after ACS. Factor Xa is important for the coagulation pathway and also plays a role in cellular proliferation and inflammation. It may thus be an attractive target for therapeutic intervention in ACS. Recently, various oral factor Xa inhibitors have been studied as potential treatment options for ACS. This review will focus on currently available data to evaluate the possible role of factor Xa inhibitors in the management of patients with ACS.

Topics: Acute Coronary Syndrome; Administration, Oral; Azepines; Benzamides; Factor Xa Inhibitors; Humans; Morpholines; Pyrazoles; Pyridones; Rivaroxaban; Thiophenes; Treatment Outcome

Acute coronary syndrome (ACS) occurs as a result of atherosclerotic plaque rupture and subsequent platelet activation and coagulation leading to thrombus formation and coronary occlusion. Thrombin and activated factor X (FXa) are key elements in the coagulation cascade. The use of anticoagulants in ACS, both in the acute phase and in the long term, has improved prognosis by reducing thrombotic events, but is associated with an increased risk of bleeding. In recent years, new oral anticoagulants have been developed that do not require monitoring and produce a lower risk of bleeding. Rivaroxaban is the only drug with a favorable risk-benefit profile in patients with ACS. The ATLAS ACS TIMI 2-51 is the first phase III trial demonstrating that the addition of low-dose rivaroxaban to optimal antiplatelet therapy reduces mortality, cardiovascular mortality, infarct or stroke without significantly increasing fatal bleeding.

Topics: Acute Coronary Syndrome; Administration, Oral; Anticoagulants; Azepines; Azetidines; Benzamides; Benzimidazoles; Benzylamines; beta-Alanine; Clinical Trials, Phase III as Topic; Dabigatran; Drug Administration Schedule; Humans; Morpholines; Pyrazoles; Pyridones; Rivaroxaban; Thiophenes

Anticoagulant therapy, known as warfarin, has been underused despite its marked benefit from embolic prevention. The intricate maintenance has made physicians constrained the use of warfarin for the many decades. Facing the 21(st) century, several new anticoagulants which inhibit single coagulant factor, such as activated factor X (Xa) or activated factor II (thrombin), has been developed. We now have selective thrombin inhibitor, dabigatran, already rolled out in clinical practice around the world. Among these drugs, four new Xa inhibitors are in final developing stage. This article reviewed the current status of new Xa inhibitors. Rivaroxaban leads the other Xa inhibitors in distribution. The phase III clinical study called ROCKET AF study had been completed and recently published. Statistical non-inferiority was clearly established compared to regular warfarin therapy. The Japanese rolled J-ROCKET AF study with 1,000 patients and the usage of reduced dose of rivaroxaban has made a similar outcome and safety end points compared to the initial ROCKET AF study. ARISTOTLE study, a phase III clinical study of apixaban has also been finished this year and will be presented soon. A phase III study of using edoxaban, a Japanese manufactured Xa inhibitor, named ENGAGE AF-TIMI 48 will be completed by next year. Darexaban, another Japan-made Xa inhibitor is in its preparation of phase III trial following favorable results of its late phase II study (OPAL-2). Having every trial with its favorable outcome, multiple alternatives of Xa inhibitors will be out in practice in no distant future. In addition, we must be aware to have a deliberate evaluation for each result, even pharmacological profiles of each Xa inhibitors with a 12 hour half-life period shows similarity, the difference in twice-daily dosing with once a day, or the difference in severity of patients' atrial fibrillation risk factor each trial contains might affect the results of phase III trials.

Topics: Anticoagulants; Atrial Fibrillation; Azepines; Benzamides; Factor Xa Inhibitors; Humans; Morpholines; Pyrazoles; Pyridines; Pyridones; Rivaroxaban; Stroke; Thiazoles; Thiophenes

Topics: Azepines; Benzamides; Blood Coagulation; Dose-Response Relationship, Drug; Factor Xa Inhibitors; Fibrinolytic Agents; Glucuronides; Humans; Morpholines; Predictive Value of Tests; Prothrombin Time; Pyrazoles; Pyridones; Rivaroxaban; Sensitivity and Specificity; Thiophenes